1. Field of the Invention
The present invention relates to a laser beam printer for providing paper one by one. More particularly, the present invention relates to an improved laser beam printer with variable paper feeding capacity. The present invention permits plural paper cassettes with different paper holding capacities to be easily and selectively mounted in the printer body.
2. Discussion of Related Art
Today, a laser beam printer is used for relatively high quality printing on a large scale. Thus, the laser beam printer requires a paper delivery and feeding that is relatively exact. If the paper supply is either too much or too little, this may either raise the cost of manufacturing or unnecessarily increase the size of the laser beam printer or even increase the chance of breakdown by requiring more fragile parts. Thus, a paper supply that is efficient, reliable, easily manufactured, and suitable for a laser beam printer is in demand. Among contemporary practice on this matter, Firl et al. (U.S. Pat. No. 5,581,289, Multi-Purpose Paper Path Component For Ink-Jet Printer, Dec. 3, 1996) discusses a paper path component of a unitary structure. The component permits paper to be loaded manually via a second manual feed path, through a housing. Upon opening a rear access door in the housing, such component is easily removable to facilitate operator access to the paper path and electrical components. Okada (U.S. Pat. No. 5,563,698, Sheet Supply Apparatus Having Manual Insertion Guide, Oct. 8, 1996) discusses a manual insertion guide for supporting a manually inserted sheet. The manual insertion guide has side regulating members for regulating the side edges of the manually inserted sheet. Belec et al. (U.S. Pat. No. 5,415,386, Vertical Feeding System For Inserter, May 16, 1995) discusses an apparatus including: a document transport; at least two hoppers located adjacent the documents on edge; a device for continuously conveying the documents through the document transport. The apparatus also includes a device for intermittently feeding the documents from the hoppers to the document transport. Tokuda (U.S. Pat. No. 5,201,507, Cassette Type Sheet Supplying Device For Using A Plurality Of Standard Cassettes Or A Single Large Cassette, Apr. 13, 1993) discussing joining two or more adjoining spaces for installing standard cassettes therein. The adjoining spaces are joined into a continuous space to enable a large cassette to be installed in lieu of two standard cassettes. Naruki (U.S. Pat. No. 5,000,596, Tray Assembly Of A Printer, Mar. 19, 1991) discusses a pair of plate-shaped adapters detachably attached to the interior sides of the side walls of the manual feed tray. The interior side surfaces of the adapters determine, when attached to the manual feed tray, the lateral position of the sheet of paper fed into the printer from the manual feed tray. When the manual feed tray is used without the adapters, the interior side surfaces of the side walls of the manual feed tray determines the lateral position of a manually fed sheet of paper. From my study of the contemporary practice and art, I find that there is a need for a more effective paper supply to a laser beam printer that permits attachment of paper cassettes of different sizes.